The present invention relates to location pins and, more particularly, to location pins used to orient a stamping die on a bolster.
In order to perform a high-quality stamping process it is necessary to align the male and female die components relative to each other with high precision. This requires that the die components be located on their respective bolsters with high precision. Further, to maintain such high precision over repeated stamping operations, it is necessary that the die components not vary from the locations determined when the dies are first attached to their respective bolsters.
In order to effect proper placement of dies upon bolsters, location pins are used. Typically, a location pin is precision ground and located within complementary pin recesses formed in the die and bolster. However, in order to facilitate mounting of the die upon the bolster, especially in situations when the die may be juxtaposed to the bolster in a slightly skewed relation during mounting, it is necessary to provide a clearance between the location pin and the die and bolster pin recesses within which it is mounted. Such a clearance is on the order of 1.1 to 1.5 mm for the pin and die, and 0.3 to 0.5 mm for the pin and bolster. With such clearances, movement of as much as 2.0 mm may occur, which is unacceptable. As a result of these clearances, it is necessary to bolt the die into place after it is mounted upon the bolster in order to prevent slight movement of the die during a stamping operation.
An example of such a mounting mechanism is disclosed in Japanese Patent No. 63-138926. That patent discloses a die having a peripheral flange which is engaged by a lug which is pivotably attached to an associated bolster. The lug is pivoted into engagement with the die flange and is bolted to the bolster in order to clamp the die to the bolster. Typically, such a clamping mechanism is used in conjunction with location pins which provide a somewhat rough placement of the die.
A disadvantage with such die-mounting mechanisms is that they require additional labor and components for precise location of a die upon a bolster. Accordingly, there is a need for a mounting mechanism for precise location of a die upon a bolster which eliminates the need for mounting bolts, at least in instances where a lower die is mounted on top of a bolster.